CVE-2023-33855 in Common Cryptographic Architecture
Summary
by MITRE • 03/26/2024
Under certain conditions, RSA operations performed by IBM Common Cryptographic Architecture (CCA) 7.0.0 through 7.5.36 may exhibit non-constant-time behavior. This could allow a remote attacker to obtain sensitive information using a timing-based attack. IBM X-Force ID: 257676.
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Analysis
by VulDB Data Team • 07/26/2025
The vulnerability identified as CVE-2023-33855 affects the IBM Common Cryptographic Architecture (CCA) version 7.0.0 through 7.5.36, presenting a significant security risk through its non-constant-time behavior during RSA operations. This flaw represents a critical concern for cryptographic systems that rely on consistent execution timing to prevent information leakage. The vulnerability specifically manifests when RSA cryptographic operations are executed within the CCA framework, creating opportunities for attackers to exploit timing variations in the computational process.
The technical nature of this vulnerability stems from the implementation of RSA operations within the CCA cryptographic library where execution times vary based on the input data being processed. This non-constant-time behavior creates measurable timing differences that can be observed and analyzed by attackers. When cryptographic operations do not execute in constant time, the duration of computation becomes dependent on the secret values being processed, which directly violates fundamental principles of secure cryptographic implementation. The vulnerability falls under the category of timing side-channel attacks as described in the CWE-385 weakness classification, specifically addressing the issue of timing information leakage through execution time variations.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables remote attackers to potentially reconstruct sensitive cryptographic keys or other confidential data through sophisticated timing analysis techniques. Attackers can leverage this weakness to perform statistical analysis on timing measurements to infer information about the cryptographic operations being executed. This type of attack is particularly dangerous because it can be executed remotely without requiring direct access to the target system, making it a significant threat to any organization relying on IBM CCA for cryptographic operations. The vulnerability's potential for remote exploitation aligns with ATT&CK technique T1059.001 for remote code execution and T1552.004 for credential access through timing-based side-channel attacks.
Organizations utilizing IBM CCA versions 7.0.0 through 7.5.36 should immediately implement mitigations to address this vulnerability, including upgrading to patched versions of the software where available. The recommended approach involves applying the latest security patches provided by IBM to ensure constant-time execution of cryptographic operations. Additionally, system administrators should consider implementing monitoring solutions that can detect anomalous timing patterns in cryptographic operations, as this may indicate attempted exploitation of the vulnerability. Network segmentation and access controls should be reviewed to limit potential attack surfaces, while cryptographic key management practices should be enhanced to minimize the impact of potential information leakage. The remediation process should also include thorough testing of patched systems to ensure that the constant-time behavior has been properly restored without introducing regressions in system functionality.